CalDigit HDPro - Manual (Page 13)

13 C. Installing the PCI card
Mac
4. Always put the PCI card in Slot #3 or Slot #4 to
obtain the optimal performance.
PLEASE NOTE:
If you have a MacPro Dual Core 2.0GHz; 2.66GHz;
3.0GHz or a MacPro Quad Core 3.0GHz and
have an AJA or Blackmagic Design capture card
installed on your computer, please follow these
instructions:
Launch Expansion Slot Utility at the following path:
/System/Library/CoreServices